How strong are those winds? Which of the following is a stronger warning - Storm, Gale or Strong? And how many sailors are aware that in late 2006 the Bureau of Meteorology changed the way it describes wind conditions in the forecasts and warnings for Australian coastal waters when there is severe weather?

On 1 November 2006 the Bureau introduced the terms 'Storm Force' and 'Hurricane Force' to describe wind conditions during extreme weather events that may affect coastal waters. This is in line with international standards. Prior to then a Storm Warning was the highest warning given by the Bureau in non-tropical regions. The bureau will now issue warnings whenever strong winds, gales, storm force or hurricane force winds are expected.
The old and new wind ranges are illustrated below:

It is also essential to be aware that wind gusts can be 40 percent stronger than the forecast so if you are planning boating holidays in Australia you need to add 40% to the forecast wind speed to take into account the gusts that may occur. Maximum waves may be up to twice the height in the forecast. So some waves will be higher and some lower than the forecast height but one in every 100 waves is likely to be 50% higher, one in every 500 waves 76%. This increases to 86% for one wave in every 1,000 waves and to 95% for one in every 2,000 waves.

For instance, a partial extract would read: 'Sydney Coastal Waters, Broken Bay to Port Hacking and 60nm seawards' states 'Storm Force Wind Warning. Wind: S/SW  35/45 knots, reaching 40/55 knots at times, chiefly offshore, during the morning. Sea: 5 to 7 metres'. This means that vessels could expect gusts of 77 knots with seas up to 14 metres.

According to the Bureau wind warnings for coastal waters attempt to provide around a 24-hour lead time and are normally reviewed every six hours.

Sailors around the world (whether they use the metric system or not) measure the wind speed in units called knots - (nautical miles).

Most sailors ignore the difference between nautical miles and statute miles and just consider knots to be equal to miles per hour... Living in a metric-system country its handy to know that 1 knot = 1.852 kilometres per hour... in practical terms it would be close enough to just multiply the knots per hour x 2 to get kilometres per hour.

Fortunately, you have another way to judge wind speed - by looking at the water. The chart below was developed by Admiral Beaufort of the British Navy in 1805. He defined wind speed in terms of a single number - the Beaufort Force. In some parts of the world, marine forecasts are still reported in these units, although using knots or metres/second is more common. The best thing about the Beaufort Scale is the remarks about the water's surface, shown in the "water surface conditions" column.

Here's a table to help you understand the relationship between wind and waves.

*Devised in 1805 by Admiral Beaufort RN.
** Notes for a bareboat skipper

This relationship between what the surface of the water looks like and the wind speed really works. Guessing the wind speed when you're out on the water is fun - and good practice, too.

One of the tips that always seems to come in handy is the one for Force 4. At around 12 knots, a few whitecaps are definitely apparent on the surface.

Of course, these descriptions of the water's surface only apply in areas where the wavelets and waves have a long enough distance to build up. For winds up to about 20 knots, that means at least half a mile of open water in the direction the wind is coming from.

Riding Out A Cyclone in the Whitsundays

In the unlikely event that you are caught 'with your pants down' while on a Whitsundays yacht charter, you will need to find an appropriate anchorage and prepare for the worst. Traditionally, you would run your charter yacht into a sheltered creek...then tie-up or anchor among the mangroves.

Some of the best Whitsunday anchorages in this respect are

• Trammel Bay
  
• Funnel Bay
  
• Woodcutter Bay
  
• Upper Gulnare Inlet

The advent of man-made harbours in the islands and marinas on the mainland has had some affect on traditional behaviour; Hamilton Harbour at the Hamilton Island Resort is now used by many of the Whitsunday island cruise boats as their cyclone anchorage, as is Abel Point Marina at Airlie Beach on the mainland. How well all of these will stand up to a real cyclone has yet to be proven, and hopefully it never will be.

Traditional cyclone anchorages in creeks are obviously shallow and must be entered with a tide that gives you a little more water than your draught. Among mangroves, there are probably not too many rocks around, and your charter yacht or cruiser will settle comfortably in soft mud as the tide goes out.

Don't get too close to the shore line; stay amongst the mangroves and allow enough room for the boat to lay over however much it will. A powerful motor left tickling over slowly in reverse will wash mud from under the boat and may prevent the angle of heel from becoming uncomfortable. If you are fortunate enough to find a natural 'hole' the boat will hardly lean over at all.